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Xamarin displayalert not showing

I have xamarin form application and i connected it signalr not running my void. I searched on internet but I can't find anything about this. And this is my code
Myhub.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNet.SignalR.Client;
namespace PharmClient
{
class MyHub
{
string url = "https://webapplication11-co5.conveyor.cloud/";
HubConnection Connection;
IHubProxy ProxyOFServer;
public delegate void Error();
public delegate void MessageRecieved(string _data);
public event Error CoonectionError;
public event MessageRecieved OndataRecieved;
public delegate void Completed();
public event Completed OnCompleted;
public void Connect()
{
Connection = new HubConnection(url);
ProxyOFServer = Connection.CreateHubProxy("MuHub");
Start().ContinueWith(task => { if (task.IsFaulted) { CoonectionError?.Invoke(); } else { OnCompleted?.Invoke(); } });
}
public Task Start()
{
return Connection.Start();
}
public void SendData(string data)
{
ProxyOFServer.Invoke<string>("SendMessage", data);
}
public void Recive( )
{
ProxyOFServer.On<string>("Sentdata", data => { OndataRecieved?.Invoke(data); });
}
}
}
MainPage.xaml.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
using System.Threading;
namespace PharmClient
{
// Learn more about making custom code visible in the Xamarin.Forms previewer
// by visiting https://aka.ms/xamarinforms-previewer
[DesignTimeVisible(false)]
public partial class MainPage : ContentPage
{
MyHub ConnectServer = new MyHub();
public MainPage()
{
InitializeComponent();
NavigationPage.SetHasNavigationBar(this, false);
ConnectServer.OnCompleted += ConnectServer_OnCompleted;
ConnectServer.CoonectionError += ConnectServer_CoonectionError;
ConnectServer.Connect();
}
private void ConnectServer_OnCompleted()
{
DisplayAlert("Connected", "Good", "O");
}
private void ConnectServer_CoonectionError()
{
DisplayAlert("Failed", "Bad", "Ok");
}
private void SerchDrug_Clicked(object sender, EventArgs e)
{
Navigation.PushAsync(new SearchDrug());
}
}
}
When connection failed ConnectionError event run but Connection will be successfully OnCompleted event won't run. I am student. This is part of group work. What is problem my code any Help. I can't found anything. Thanks for attention

As your title suggest, you have an issue with displaying a dialog box.
Try going through the documentation (here) once for complete understanding, you have to await the process of displaying DisplayAlert.
Add await & async to your methods.
Try this -
private async void ConnectServer_OnCompleted()
{
await DisplayAlert("Connected", "Good", "O");
}
private async void ConnectServer_CoonectionError()
{
await DisplayAlert("Failed", "Bad", "Ok");
}
If you have some issues regarding, let me know.

You should await connection not fire and forget. Example:
private HubConnection connection;
private IHubProxy proxy;
public event EventHandler<ChatMessageObject> OnMessageReceived;
public async Task Connect()
{
try
{
await connection.Start();
await proxy.Invoke("Connect"); // example method in your backend
proxy.On("messageReceived", (int userId, string name, string message, DateTime messageDateTime) => OnMessageReceived(this, new ChatMessageObject
{
FromUserId = userId,
UserName = name,
MessageText = message,
MessageDateTime = messageDateTime
}));
}
catch (Exception ex)
{
//handle exceptions
}
}

Windows Service (in C#) that can call a Python script that runs infinitely?

From what I understand, when you run a Windows Service, it calls 'onStart()' and will say that the service is 'starting' in the task manager until the 'onStart()' method runs through completely, to which it then says "running". I would like to create a thread to start a Bluetooth Advertising Script (written in Python3) that will advertise continuously whenever it is not connected to a device. When I try to create a thread and run the script, the service usually just displays "starting' in the task manager and never actually says "running", because the thread that I call within 'onStart()' to initiate the script never finishes I guess. Is there a way to get the service to start, only starting the thread after it as finished executing the 'onStart()'?
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Timers;
using System.Threading;
using System.Security.Permissions;
namespace WindowsService1
{
//--------------------------------------------------------------------------------------------------------------------------------------------------
public partial class Service1 : ServiceBase
{
//-------------------------------------------------------------------------
public Service1() { InitializeComponent(); }
//-------------------------------------------------------------------------
private Boolean _started;
public event System.EventHandler serviceChanged;
Service1 serv = new Service1();
static ThreadStart start = new ThreadStart(Adv_Py_Script);
Thread Adv_Py_ScriptThread = new Thread(start);
//Start_Adv s = new Start_Adv();
//Thread thread1 = new Thread(new ThreadStart(s.Adv_Py_Script));
//-------------------------------------------------------------------------
protected override void OnStart(string[] args)
{
isStarted = true;
Thread.Sleep(5000);
}
//-------------------------------------------------------------------------
protected virtual void onServiceChanged() { serviceChanged?.Invoke(this, EventArgs.Empty); }
//-------------------------------------------------------------------------
public Boolean isStarted
{
get { return _started; }
set
{
_started = value;
onServiceChanged();
}
}
//-------------------------------------------------------------------------
protected override void OnStop()
{
isStarted = false;
serv.killPyThread(Adv_Py_ScriptThread);
base.OnStop();
// wait for threads to stop
Adv_Py_ScriptThread.Join(60);
try
{
string error = "";
// Messaging.SMS.SendSMSTextAsync("5555555555", "Messaging Service stopped on " + System.Net.Dns.GetHostName(), ref error);
}
catch
{
// yes eat exception if text failed
}
}
//-------------------------------------------------------------------------
[SecurityPermissionAttribute(SecurityAction.Demand, ControlThread = true)]
public void killPyThread(Thread thread)
{
thread.Interrupt();
thread.Abort();
}
//-------------------------------------------------------------------------
private static void Adv_Py_Script()
{
string fileName = #"C:\Users\bakere1\A19149\Projects\BLE_Advertiser.py";
Process p = new Process();
p.StartInfo = new ProcessStartInfo(#"C:\Python36_64\python.exe", fileName)
{
RedirectStandardOutput = true,
UseShellExecute = false,
CreateNoWindow = true
};
p.Start();
}
}

While there might be other problems, the first one is that the Local Service account that your service (probably) runs as doesn't have permissions to the location C:\Users\bakere1\A19149\Projects\
If you change the "Run As" account to something with permissions, you'll get farther. I'm not a big python geek, but if your py app requires any sort of user I/O it will fail, since there is no console session assigned to it.
Also, if you have roaming profiles, the service gets started at before the user folder is available, so it will hang or fail.

Windows service webs server cannot connect to other machines

I am attempting to design a windows service that contains a web server to do basic get request handling. Requests from the localhost work just find but I am unable to process requests from other machines. On python, setting the IP address to 0.0.0.0 allows the server to process requests from any IP on the network. I have found examples that use http://*:port/ or http://+:port/ to obtain this functionality in C# but these have not worked for me.
I am currently starting a HttpListener (WebServer.cs) when the windows service (UsherService.cs) receives its start command. If there is a better way to do this, I'd appreciate that answer as well.
Program.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;
namespace UsherService
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
static void Main()
{
ServiceBase[] ServicesToRun;
ServicesToRun = new ServiceBase[]
{
new UsherService()
};
ServiceBase.Run(ServicesToRun);
}
}
}
UsherService.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;
namespace UsherService
{
public partial class UsherService : ServiceBase
{
WebServer ws;
public UsherService()
{
InitializeComponent();
}
public static string SendResponse(HttpListenerRequest request)
{
return string.Format("<HTML><BODY>My web page.<br>{0}</BODY></HTML>", DateTime.Now);
}
protected override void OnStart(string[] args)
{
try
{
ws = new WebServer(SendResponse, "http://*:5000/");
ws.Run();
System.IO.File.AppendAllText(#"C:\Users\kburd\Desktop\WriteText.txt", "Started Successfully");
}
catch(Exception e)
{
System.IO.File.AppendAllText(#"C:\Users\kburd\Desktop\WriteText.txt", e.Message);
}
}
protected override void OnStop()
{
System.IO.File.AppendAllText(#"C:\Users\kburd\Desktop\WriteText.txt", "Stopped Successfully");
}
}
}
WebServer.cs
using System;
using System.Net;
using System.Text;
using System.Threading;
public class WebServer
{
private readonly HttpListener _listener = new HttpListener();
private readonly Func<HttpListenerRequest, string> _responderMethod;
public WebServer(string[] prefixes, Func<HttpListenerRequest, string> method)
{
if (!HttpListener.IsSupported)
throw new NotSupportedException(
"Needs Windows XP SP2, Server 2003 or later.");
// URI prefixes are required
if (prefixes == null || prefixes.Length == 0)
throw new ArgumentException("prefixes");
// A responder method is required
if (method == null)
throw new ArgumentException("method");
foreach (string s in prefixes)
{
_listener.Prefixes.Add(s);
System.IO.File.AppendAllText(#"C:\Users\kburd\Desktop\WriteText2.txt", s);
}
_responderMethod = method;
_listener.Start();
}
public WebServer(Func<HttpListenerRequest, string> method, params string[] prefixes)
: this(prefixes, method) { }
public void Run()
{
ThreadPool.QueueUserWorkItem((o) =>
{
Console.WriteLine("Webserver running...");
try
{
while (_listener.IsListening)
{
ThreadPool.QueueUserWorkItem((c) =>
{
var ctx = c as HttpListenerContext;
try
{
string rstr = _responderMethod(ctx.Request);
byte[] buf = Encoding.UTF8.GetBytes(rstr);
ctx.Response.ContentLength64 = buf.Length;
ctx.Response.OutputStream.Write(buf, 0, buf.Length);
}
catch { } // suppress any exceptions
finally
{
// always close the stream
ctx.Response.OutputStream.Close();
}
}, _listener.GetContext());
}
}
catch { } // suppress any exceptions
});
}
public void Stop()
{
_listener.Stop();
_listener.Close();
}
}

The firewall was blocking the localhost from communicating to other devices on the network. I had to allow for communication over that port

How to wait until thread process finishes in C# using (Delegate Method)

Kindly help me. My idea is to continually print Numeric values form 0 to 1000 using thread concept. In case unexceptionally my application closes, how can I write the code WAITING for currently running thread tasks to complete.
Here by i mention sample code...
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.Runtime.Remoting.Messaging;
using System.IO;
namespace Test_AsyncFactorCaller
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public bool Work()
{
int nSleep = 100;
WriteMessage(string.Format("Going to Thread Sleep State for {0} sec", nSleep));
for (int i = 0; i < nSleep; i++)
{
WriteMessage(string.Format("Sleeping = {0}", i));
Thread.Sleep(1000);
}
WriteMessage("Going to Thread Wakeup State");
return true;
}
public void Work_Done(IAsyncResult result)
{
WriteMessage("Work_Done");
AsyncFactorCaller t = (AsyncFactorCaller)((AsyncResult)result).AsyncDelegate;
bool bResult = t.EndInvoke(result);
WriteMessage(string.Format("Result {0}",bResult));
result.AsyncWaitHandle.Close();
}
public void WriteMessage(string sMessage)
{
using (StreamWriter sw = new StreamWriter(#"C:\ThreadLog.txt", true))
{
sw.WriteLine(sMessage);
sw.Close();
}
}
private void btn_asyncCaller_Click(object sender, EventArgs e)
{
try
{
AsyncFactorCaller dGate_caller = new AsyncFactorCaller(Work);
AsyncCallback Completed_callBack = new AsyncCallback(Work_Done);
AsyncOperation asyncOperation = AsyncOperationManager.CreateOperation(null);
IAsyncResult result = dGate_caller.BeginInvoke(Completed_callBack, "Test thread");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString());
}
}
public delegate bool AsyncFactorCaller();
}
}

If you are really sure that this is what you need to do, try using a WaitHandle.
AutoResetEvent _blocker = new AutoResetEvent(false);
//In background thread
_blocker.Set();
//Where you want to wait for it
_blocker.WaitOne();

Getting a Service to Run Inside of an Azure Worker Role

I have a windows service that I need to migrate to onto Azure as a Worker Role. Everything builds fine in my Azure solution. However, when I upload everything only the web role starts. The worker role instance gets stuck cycling between the following two statuses without ever starting.
Waiting for the role to start...
Stabilizing role...
Since the instance is failing to start I suspect my problem lies somewhere in my WorkerRole.cs code. Below you'll find that code. I've also included the code for the service in case it's relevant to the question. What did I do wrong?
This is my WorkerRole.cs file:
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Threading;
using Microsoft.WindowsAzure;
using Microsoft.WindowsAzure.Diagnostics;
using Microsoft.WindowsAzure.ServiceRuntime;
using Microsoft.WindowsAzure.StorageClient;
using System.ServiceProcess;
namespace SBMWorker
{
public class WorkerRole : RoleEntryPoint
{
public override void Run()
{
ServiceBase[] ServicesToRun;
ServicesToRun = new ServiceBase[]
{
new Service1()
};
ServiceBase.Run(ServicesToRun);
//Thread.Sleep(Timeout.Infinite);
}
}
}
This is my Service1.cs code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using Lesnikowski.Mail;
namespace SBMWorker
{
public partial class Service1 : ServiceBase
{
private System.Timers.Timer mainTimer;
public Service1()
{
InitializeComponent();
}
protected override void OnStart(string[] args)
{
try
{
// config the timer interval
mainTimer = new System.Timers.Timer(foo.Framework.Configuration.SecondsToWaitBeforeCheckingForEmailsToProcess * 1000);
// handling
mainTimer.Elapsed += new System.Timers.ElapsedEventHandler(mainTimer_Elapsed);
// startup the timer.
mainTimer.Start();
// log that we started
foo.Framework.Log.Add(foo.Framework.Log.Types.info, "SERVICE STARTED");
}
catch (Exception ex)
{
try
{
foo.Framework.Log.Add(ex, true);
}
catch{throw;}
// make sure the throw this so the service show as stopped ... we dont want this service just hanging here like
// its running, but really just doing nothing at all
throw;
}
}
protected override void OnStop()
{
if (mainTimer != null)
{
mainTimer.Stop();
mainTimer = null;
}
// log that we stopped
foo.Framework.Log.Add(foo.Framework.Log.Types.info, "SERVICE STOPPED");
}
void mainTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
mainTimer.Stop();
bool runCode = true;
if (runCode)
{
try
{
// call processing
foo.Framework.EmailPackageUpdating.ProcessEmails();
}
catch(Exception ex)
{
try
{
// handle error
foo.Framework.Log.Add(ex, false);
}
catch { throw; }
}
}
mainTimer.Start();
}
}
}

I think the root of your problem is that you basically can't install a service programmatically in Azure roles. You need to use a .cmd startup script and the InstallUtil to properly install the service then you can start it from the script or from your code (think from the script is often preferred for order-of-execution reasons).
Here's a blog post on how to do it: http://blogs.msdn.com/b/golive/archive/2011/02/11/installing-a-windows-service-in-a-worker-role.aspx
Here's another blog post that takes a little different approach (creating a .Net app that executes the installation, but again as part of the startup script): http://www.bondigeek.com/blog/2011/03/25/runninginstalling-a-windows-service-in-an-azure-web-role/
Hope that helps